Daidzin

In this study, AB (wild-type), Nrf2-mutant (nfe2l2a^fh318) [13 (link)], and Nrf2-knockout (nfe2l2a^it321) zebrafish larvae were used. Both mutant and knockout lines were maintained by PCR-based genotyping. The former was maintained as described previously [14 (link)]. For the latter, the primer sets 5′-TATTGTGCAGCCCTAGTGTG and 5′-TAGCTGAAGTCGAACACCTC were used. Larvae used in these experiments were obtained from parents of AB, homozygous nfe2l2a^fh318 or homozygous nfe2l2a^it321 by natural mating. The nfe2l2a^fh318 and nfe2l2a^it321 lines can be obtained from the Zebrafish International Resource Center (http://zebrafish.org (accessed on 2022 January 5)) and the National BioResource Project Zebrafish (https://shigen.nig.ac.jp/zebra (accessed on 2022 January 5)), respectively.
Genistein, glycitin, glycitein, daidzin, daidzein, equol, and cinnamaldehyde were purchased from FUJIFILM Wako (Osaka, Japan). Genistin and sulforaphane were purchased from NAGARA Science (Gifu, Japan) and LKT Laboratories (St. Paul, MN, USA), respectively. For stock solutions, hydrogen peroxide and sodium arsenite were dissolved in MilliQ water (Merck-Millipore Billerica, MA, USA), sulforaphane in ethanol, and isoflavone compounds in dimethyl sulfoxide. They were diluted to final concentrations with E3+ medium (5 mM NaCl, 0.17 mM KCl, 0.33 mM CaCl₂, 0.33 mM MgSO₄ and 0.1 µg/mL methylene blue).

Apigenin, Apigenin 7-O-glucoside, daidzein, daidzin, daidzin 6″-O-acetate, daidzin 6″-O-malonate, genistein, genistin, genistin 6″-O-acetate, genistin 6″-O-malonate, glycitein, glycitin, glycitin 6″-O-acetate, and glycitin 6″-O-malonate were purchased from Fujifilm Wako Pure Chemical Industries, Ltd. (Osaka, Japan). Coumestrol, dimethyl sulfoxide (DMSO), kaempferol, kaempferol 3-O-glucoside (astragalin), isoquercitrin, isorhamnetin, luteolin, quercetin, and rutin were purchased from Sigma-Aldrich Co., LLC (St. Louis, MO, USA). The purities of the authentic compounds are listed in Table S1. Two quercetin diglycosides, two quercetin triglycosides, two kaempferol diglycosides, and three kaempferol triglycosides were purified from SLs. Mass-grade formic acid, acetonitrile, methanol, and water were purchased from Thermo Fisher Scientific Inc. (Waltham, MA, USA). Other chemicals used were of American Chemical Society grade or higher.

Eight reference standards (albiflorin, cinnamaldehyde, cinnamic acid, daidzin, glycyrrhizin, liquiritin, paeoniflorin, and puerarin) were purchased from Wako (Osaka, Japan) and the purities of these reference standards were greater than 98.0%, as evaluated via high-performance liquid chromatography (HPLC). The HPLC-grade reagents, methanol, acetonitrile, and water were obtained from J.T. Baker (Phillipsburg, NJ, USA). Analytical-grade glacial acetic acid was procured from Junsei (Tokyo, Japan).